Reusable shopping bags could harbor bacteria

TUCSON, AZ — A recent study revealed that most consumers surveyed never wash their reusable bags between uses, permitting bacteria to grow, according to a press release.

The peer-reviewed study, completed by University of Arizona Microbiologist Dr. Charles Gerba, found that large numbers of bacteria were found in almost all bags and that coliform bacteria were found in half of those tested, while eight percent of bags contained Escherichia coli (E. coli), the release stated.

According to the release, the study tested 87 reusable bags obtained at random from grocery shoppers in California and Arizona during the early summer of 2010; each bag was swabbed for bacteria and laboratory tested.

"I was surprised to learn through this study that only three percent of shoppers surveyed actually said they washed their reusable bags between uses. More surprising were the numbers of people who stated they used the bags not only for food shopping, but also to transport clothing and other products to and from work and the gym," said Dr. Gerba.

"There has been a growing movement to use reusable bags when we shop, but without proper washing, these bags can expose our families to bacteria that can cause illness," Gerba added.

Reusable bags are particularly susceptible to contamination since remnants of meats and dairy products may seep out of packaging remain in bags unless washed out, resulting in bacterial growth, the release noted.